The first step was the fields layout design. The main considerations for this was to optimize the field shape and furrow direction to promote rows lengths and headland angles for more efficient mechanized farming and irrigation while restricting required earthwork to achieve this.
In addition to furrow direction, the main design variable came down to optimizing the placement of the tail drain alignment and parallel head land beside it (for next field down) to achieve consistent slope for the drain and the layflat pipe with acceptable earthworks. The optimised taildrain/headland alignment achieved an average slope of 0.1% which suits the drainage and layflat pipe nicely.
OptiSurface Designer's Drainage Analysis Tool can be used to test different furrow directions and field boundaries quickly to see the proportion of the field that would have drainage problems (standing water) and therefore need earthworks to rectify. The figure below shows the original topography and where water would pond if no earthworks work done with the final field layout and furrow direction selected (drag the slider). The areas with drainage problems are minimal indicating a good field layout design.